Hydraulic shock absorber



5, 1925 1,536,531 J. H. SClflERMANN HYDRAULIC SHOCK ABSORBER Filed April 22, 1924 ffl?? FIG. 2

lvNvENToR.

MLM

Patented May 5,1925.

JOHN HENRY sonnnnann, or PITTSBURGH, rnNNsYLvAma.

HYDRAULIC SHOCK ABSORBER.

Application inea Apro. 2a, 192e. serial No. 7025,19?.

llc it known that I, JOHN HENRY SCHER- nmrx. a citizen ot' the United States, and a resident of Pittsburgh, -in the county of Ulen'heny andSt-ayte of Pennsylvania, have im'onted anew and useful Improvement in l'lydraulic Shock litbsorbers; and lf do here by declare the following to be a full, clear, and exact description thereof.

My invention relates to hydraulic shock absorbers and particularly to means for absorbing the momentum of a moving volume of waiter. A

The sudden stoppage of Water flow in a distributing' system, as by the quick closing oi a faucet, results in hammerlilre shocks 'that produce objectionable noises and imposes excessive strains upon the pipes.

Heretotorc, various means have been proposed for taking up these shocks, such as by 'air chambers communicating directly with the water system and by a tightditting movable piston betweeil the air chamber and the Water line. .lin the Aliorn'ier case the air chamber -becomes filled with Water after a time. thus rendering; it ineffective to absorb shocks, and in the latter case the constr-uction is expensive, besides which Water Will eventually find iis'way past 'the piston, thus destroying its effectiveness as a shock absorber.

The object' .of my invention is to provide a structure' wherein objections such as. the foregoing are eliminate One form which my invention may take is 'shown inthe accompanying drawing wherein Fig. l is a View, partiallyI in eleva tion and partially in section, of a eonstruc tion embodying my invention; Fie'. 2 is an enlarged sectional view of a portion of the apparatus of Fig. l; 3 is a 1View similar to that of Fig. 2 but showing some o the parts thereof in elevation, and Fig. 4; is a View taken on the line 4-*4 of Fig.

Referring; to the drawings, 5 is a water line to `which my invention is connected by means of a T 6. The device 'includes a tubular chamber 'i' having, a cap 8v 'to which a stem or rod 9 is secured by screw threading or otherwise. A spring seat 1() is secured to the lower end of the rodi), a piston or V,plunger 11 is slidably supported upon the rofl 9 and normally held in mid-position thereon by springs 12 and lit The spring' 1Q seats against the cap 8 and Athe upper side or the plunger .il and the spring 13 fits f a plurality of longitudinally betiileen the opposed faces of the cap 10 and the plunger l1.

The piston or plunger l1 fits the cylinder 7 with only sufficient clearance to permit free movement thereof longitudinally of the rod 9 and is provided with a tapered upper surface and a lower surface that mainly lat although it may be cup shaped tonie.n

'what ai'ter the manner shown at lll in Fig.

2. The piston l1 is further provided with disposed, downwardly tapering, grooves 15, to permit`- the Water abovethe piston to pass to the iii-ont thereof when 'the piston is moved up* 'wardly'- Vi'hile l show a plurality o'i` grooves 135, it 4will be atiparent that under some conditions of operation one groove may suice.

lVhen the `flow of Water through the pipe 5 is shut ofi' suddenly, as by a spigot 16, the impact of the moving body of'water in the pipe v.fi will be transmitted to the lower face oihe piston 11. `Tests made with the piston l1 i'nounted in a glass tube, show that the piston will move upwardly under such shocks for a distance of about one-fourth of an inch at times, but may move either more or less, depending upon conditions, and in any event will move upwardly suili cient to absorb the shock to such a degree that the hamnierlilre noises in the system are eliminated.` i

From the foregoing description it will be seen that l provide a. structure simple and eiective i n' its operation and requiring pra@ tically no attention Working order. That i claim is: l, The combination with a Water line, oi" a shock absorber comprisingr a chamber dien posed outsideoi but tapped into said line,4

vand a metallic piston iittingwithin sai' chamber and normally disposed intermedi-- ate the ends thereof. a communicating passage beine' provided between the opposite .sides of said piston.

The combination with a vWater line, oi a shock absorber therefor, cmnlnf'isincr e chamber disposed exterior of but communi eating with said line, al piston of non-yicld infr material movable therein, means for yieldingly holding said piston ata predatorA n'iincd mid-point in said chamber, and means providingT communication between the oppo site sides of said piston.

3. The combination with a Water line, oli

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to keep it in proper .ate the ends thereei', n communicating pessngo being;r provided between the opposite sides of seid piston, the snid piston tapering townrds its rear end. v

4. rEhe combination with n water line, of n shook absorber comprising n ehnniber Communicating with Suid line, n plunger fitting within seid ehnlnber and norxnnlly disposed nd means e noxiding communication between opposite sides of the plunger, the said plunger being o inpering forni at its rear side and having a substantially flat surinee at its "front side, the said flat surface 'being pro vided adjacent to its periphery with n rigid annular flange.

5. A shock absorber comprising a. chamber provided with an opening at one end, n

removable cover for the other end of thop chamber, n rod carried by said cover and extending longitudinally of the chamber, a plunger slidably supported by said rod7 and means for yieldnbly supporting the plunger :1t-n pointinterxnedinte the ends of said chamber. l

In testimony whereof I, the said JOHN HENRY SomnumNN, have hereunto set my hand.

JOHN HENRY SCHERMANN. 

